Air-cushion compression-cylinder for pressure-rollers



Patented May 17, 1881.

G. W. NICHOLS. Air Cushion Compression Cylinders for Pressure Rollers.

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(No Model.)

' c zrmiqre n m m m w n E n P N UNITED STATES PATENT OFFICE.

GEORGE W. NICHOLS, OF CLINTON, ASSIGNOR OF ONE-HALF TO THE NOV- ELTYIRON WORKS, OF DUBUQUE, IOWA.

AIR-CUSHION COMPRESSION-CYLlNDER FOR PRESSURE-ROLLERS.

SPECIFICATION forming part of Letters Patent No. 241,702, dated May 17, 1881..

Application filed October 4, 1880. (N model.)

In the accompanying drawings, which make a part of this specification,Figure 1 represents a vertical section of the upper part of a gangsaw mill taken through the centers of twin air-cushion com pression-cylinders ll, combined with the rollers 12 n. Fig. 2 is a front elevation of the upper part of the mill, having my improvement in connection with the rollers an.

dicatethe same parts.

A A represent the housings, between which the gang-saw frame I), provided with saws B, has its up-and down movements in the slides a 0. Twin cushion compression-cylinders Z Z are permanently connected with the cap A, which connects the upper ends of the housings 0 A A. Thesecylindershave pistons h h, which are provided with rods f f, the lower ends of which .have a permanent connection with the stocks f f of the pressure-rollers a n. The cylinders l l have air-chests z i, which are con- 3 5 nected together by means of the pipe it. These chests have valves 0 0, which are operated by means of the levers p p, for directing the air into either end of the cylinders, as may be required, for pressing the rollers downward or raising them upward. The pressure of lhe air is controlled bymeans of the safety-valve q, placed at the point of connection. of the airinduction pipe t with the pipe t.

I do not confine myself to the mode above described of supplying the compression-cylinders with air, as other modes may answer the purpose and produce the same results.

It will plainly appear that, as there is an equal pressure of air upon the pistons h h during all the changes in the height, the pressurerollers n n will have a uniform force at all times upon the timber being sawed, however crooked its upper surface may be in its longitudinal direction, whereas steel or rubber springs exert an uneven force upon such a surface, and are therefore unsuitable for the purpose. Like letters of reference in both figures iu- I claim as my invention- The combination of twin air-cushion compression-cylinders Z Z, having pistons 71. h, with the pressure-rollers n n of a gang-saw mill, the cylinders l I having air-chests i i, provided with valves 0 0,.and connected together by means of the air-pipe t, having an inductionpipe, t, substantially as and for the purpose above described.

GEORGE W. NICHOLS.

Witnesses:

, CHARLES W. CHASE, LE R01 B. WADLEIGH.

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